Assessment of the impact of microwave roasting on nutrient content, lipid profile, and oxidative stability of pomegranate seed oil

Abstract

The pomegranate, Punica granatum L. (Punicaceae), stands as one of the most widely employed oils in the cosmetic industry. However, due to its higher content of conjugated linoleic acid, its susceptibility to oxidation is a major challenge, with the most prominent being punicic acid. This study aimed to evaluate the effects of traditional roasting in a microwave on the lipid content, nutritional value, and oxidative stability of Moroccan pomegranate seed oil. The findings indicated a rise in the amount of oil after 15 min of roasting at 650 W, the amount of oil rose from 27.03 to 30.10 (g/100 g). However, the protein content, UV absorbance values, iodine, and saponification values were not significantly affected by a longer roasting time. The peroxide value increases with roasting (1.00 to 5.00 M.eq. O₂/kg oil). The roasting process under 350 W did not significantly alter the fatty acid composition. The total tocopherol content exhibits a decrease with increasing roasting time and power, ranging from 333.36 mg/100 g for unroasted seeds to 316.84 mg/100 g for seeds roasted under the conditions of 650 W for 15 min. The roasting process has proven to be critical for the immediate and long-term preservation of the nutritional and physico-chemical properties of pomegranate seed oil.